.parent {
    width:  300px;
    height: 40vh;
    overflow-y: scroll;
    -ms-overflow-style: none;
    }
    .parent::-webkit-scrollbar {
    display: none;
    }
    /*设置的子盒子高度大于父盒子，产生溢出效果*/
    .child {
    height: auto;
    }
    
    .child li {
    height: 50px;
    margin: 2px 0;
    background: #009678;
    }